Change in coreboot[master]: treewide: Drop unused Kconfig symbols

[Paul Menzel (Code Review)]

Attention is currently required from: Lance Zhao, Tim Wawrzynczak, Patrick Rudolph, Elyes Haouas, Felix Held.
Paul Menzel has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62362 )

Change subject: treewide: Drop unused Kconfig symbols
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Patch Set 7:

(3 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/62362/comment/b471a14d_f55de82d 
PS7, Line 7: treewide
Just use `src`?

https://review.coreboot.org/c/coreboot/+/62362/comment/040f672b_fd876f23 
PS7, Line 8: 
If easily doable, maybe list all the symbols in the body.

https://review.coreboot.org/c/coreboot/+/62362/comment/627cd035_5b4d818b 
PS7, Line 11: Signed-off-by: Elyes Haouas 
Signing of once should be enough. ;-)